Cap screw and lock device



March 6, 1945. .1. R. EMERSON CAP SCREW AND LOCK DEVICE Filed Oct. 11,1940 Patented Mar. 6, 1945 CAP SCREW AND LOCK DEVICE John R. Emerson,Flint, Warner Corporation,

of Illinois Mich., assignor to Borg- Chicago, 111.. a corporation 7Application October 11, 1940, Serial No. 360,710

1 Claim.

This invention relates to screws and locking arrangements therefor andparticularly to screw driver operated generally cylindrical headed capscrews and locking devices therefor, having special adaptation to theproblem of fastening the cover assembly of a carbureter to the floatbowl thereof.

It is the general object of this invention to provide an improvedassembly of cap screw and locking means therefor. It is a moreparticular object to provide an improved construction of generallycylindrical headed screw driver operated cap screw and locking devicetherefor. A further particular object is the provision of an improvedconstruction of generally cylindrical headed screw driver operated capscrew formed with particular reference to cooperation therewith of acomplementarily formed locking means.

A more-detailed object is the provision of an improved arrangement ofthe above character which is particularly adapted to the problem offastening the carbureter cover assembly to the carbureter float bowl.

Other more particular objects, advantages and uses of my invention willbecome apparent from a reading of the following specification taken inconnection with the appended drawing which forms a part thereof andwherein:

Fig. 1 is a broken away plan view of a carbureter assembly wherein thecover is held in place with relation to the underlying float bowl bymeans of a preferred embodiment of my invention;

Fig. 2 is a, broken away elevation corresponding generally to Fig. 1;

Fig. 3 is an exploded view of my improved cap screw and lockingarrangement and showing to special advantage the individual parts intheir relationship.

Referring more specifically to the figures of the drawing, I indicatesgenerally a broken away portion of a carbureter including a coverassembly indicated generally at II and a float bowl portion indicatedgenerally at- I2, these portions being fastened together by my novelconstruction of cap screw and lock device therefor. Referringparticularly to Fig. 3, my improved construction includes a cap screwindicated generally at l6 and comprising the usual threaded portion l1,and the generally cylindrical head portion l8. Cylindrical head I8 isformed about the periphery thereof with axially extending splines orteeth l9. As shown, the entire outer periphery of cylindrical head I8 isformed with these splines or teeth. While I prefer this con- (Cl. l5132)struction, it will nevertheless be understood that I contemplate ascoming within the broader aspects of my invention the use of a smallernumber of teeth or splines.

The usual recess 20 for cooperation with a screw-driver is provided inthe upper portion of cylindrical head l8. In addition a transverse bore2| is formed through head l8 between the axial extremities thereof forthe reception of a cotter pin 22 or other suitable fastening means for apurpose to be brought out.

Lock washer-like member or assembly indicated generally at 25 is formedwith an opening therethrough defined by teeth 24 complementary to andreceived between the spline 19 of the cylindrical head l8 between theaxial extremities thereof. As will appear, this relationship of teethand splines functions to prevent relative rotative movement betweencylindrical head l8 and the washer-like assembly 25. While I prefer toprovide this toothed relationship about the entire circumferentialextent of the opening within washer assembly 25 and about cylindricalhead I8 because of certain novel advantages presented thereby, it willnevertheless be understood that since the function of the spline andtooth relation is to prevent relative rotation, I contemplate as comingwithin the broad scope of my invention any arrangement wherein head l8and the opening in washer assembly 25 are made noncircular for thepurpose of preventing relative rotation. For example, the head l8 may bemade ovalin shape and washer assembly 25 provided with a complementarilyformed opening. Alternatively, cylindrical head l8 may be formed with asingle spline, the remainder of the periphery thereof being generallycylindrical and washer assembly 25 similarly formed with a complementarynotch arrangement for cooperation with the toothed portion of head IS.

The head l8 of screw assembly l6 may I be formed by any one of severalwell-known methods so long as the contemplated resulting structure isprovided. For example, in practice I have found that this constructioncan most readily be provided by a simple broaching operation performedon a cap screw, the head portion of which originally has a cylindricalouter periphery. It is equally apparent that other methods such ascasting and pressure molding may be employed for producing thisconstruction.

Washer-like assembly 25 is further provided with finger elements 26, twobeing disclosed. These finger elements as shown in Figs. 1 and 2 areadapted to be turned down into contact with of the cover H to thus servethe important motion of preventing the cap screw assembly I! fromworking loose in response to the usual vibrations towhich the same issubjected. In addition to the above, there is employed a split springlock washer 2 1 of the usual construction.

While w'asher assembly 25 may be provided by means of any of the wellknown methods. I prefer to form the same by a simple stamping operation.The important thing to remember-so far as the present invention isconcerned, is resulting structure as disclosed. The particular method offabricating either cap'screw assembly IE or washer-like assembly 25 doesnot constitute part of the present invention.

While I have disclosed my invention in its particular adaptation totheproblem of attaching the cover assembly of a carbureter to the floatbowl thereof, it is to be understood that in the broader aspects of myinvention I contemplate the use of this novel cap screw and lock washerassembly in other relations when the present problem exists.

While I have disclosed my invention in connection with certain specificembodiments thereof, it is to be understood that this is by way ofexample and not by way of limitation, it being my intention that theclaims be construed as broadly as permitted by the prior art.

I claim:

drical headed cap screw employed adjacent an axially extending wallportion of a structure to be held in place relative to a secondstructure by said screw, said arrangement comprising a plurality ofcoaxially extending splines or teeth formed in the outer periphery ofsaid cylindrical head. a flat sheet washer-like assembly formed with anopening defined :by radially inwardly extending complementary teeth tosaid first named teeth for reception thereabout between the axialextremities of said first named teeth and functioning to preventrelative rotative movement between said screw and said washer-likeassembly, said washer-like assembly being further provided with aplurality of radially outwardly extending finger elements adapted to bebent downwardly into engagement with said axially extending wall portionof said associated structure and serving to prevent the inadvertentworking loose of said cap screw, said cylindrical head of said cap screwbeing formed with a transverse opening therethrough, and a cotter pinreceived in said opening for preventing outward axial movement of saidwasher assembly relative to said cylindrical head. r

' JOHN R. EMERSON.

